The team Juergen Klinsmann called up for the next round of World Cup qualifiers is arguably among the best in U.S. national team history. And if things break right for the Americans on Friday in Costa Rica, the U.S. team could make history of another sort by earning a World Cup invitation with three qualifying matches left to play.

That hardly seemed likely 10 months ago, when the U.S. was a loss away from elimination in an earlier round of qualifying. But with a victory in Costa Rica, combined with a tie between Mexico and Honduras and a Jamaican win or draw at Panama, the U.S. would become the sixth nation to guarantee itself a berth for next summer's World Cup in Brazil.

What a change from February, when Klinsmann's future seemed in jeopardy after his sluggish team played a scoreless draw with Canada and managed only one goal in a loss to Honduras. Now the U.S. is riding a record 12-match winning streak and averaging more than three goals a game, while climbing back into the top 20 in the FIFA world rankings for the first time in 21/2 years.

"We've done really, really well throughout the entire year, but now it's all about finishing things off," Klinsmann said. "The good part about all of our work over the last six, eight months is we deepened our roster, we deepened our possibilities in selecting specific players and all the players not called in to Costa Rica are still in the loop going forward."

Credit much of that change to the spirit of constant competition that Klinsmann has engendered on his roster, in which no player's job is safe but no one's ever completely out of the picture, either.

Consider that six Americans called up for the Costa Rica match and the Sept. 10 qualifier against Mexico in Columbus, Ohio, were not on the U.S. team for the first six World Cup qualifiers this season. And seven players who were in uniform for the last round of qualifiers in June aren't on the team this time.

Among the additions is the Galaxy's Landon Donovan, who had to earn his way back after taking a three-month break from soccer over the winter. Donovan proved his form with a spectacular July, in which he scored seven goals with seven assists in seven games while leading a U.S. B team to the Gold Cup title.

That leaves Klinsmann with the pleasant challenge of finding playing time up front for both Donovan and forward Jozy Altidore, who has scored in five consecutive games. Plus, Klinsmann has on his roster the Seattle Sounders' Eddie Johnson, who has scored in three of his last four matches, and Aron Johannsson, a dual U.S.-Icelandic citizen who made his national team debut in last month's friendly with Bosnia-Herzegovina.

"Now it's all about putting pieces together," said Klinsmann, who will begin gathering his team in Miami on Sunday before their flight Tuesday to Costa Rica. "Once we have them in camp we'll see how they are doing and how the pieces will fit.

"Having Landon back in the picture is another really good option for us so we're looking forward to it."

If Donovan starts, it probably will be in place of Graham Zusi or Clint Dempsey, who both came to camp with questions about their fitness. There are likely to be few changes on defense, though, with the Galaxy's Omar Gonzalez anchoring a back line that has given up only one score in its last five qualifiers.

But not all the numbers favor the U.S. The Americans have never won a World Cup qualifier in Costa Rica, and this time they'll be facing a team bent on avenging a controversial loss.

Playing in a blizzard in Denver, the U.S. beat Costa Rica, 1-0, in March in a match the Central Americans felt should have been stopped. Without that victory, Costa Rica, not the U.S., would be atop the table in the six-team regional qualifier, and it would be Costa Rica, not the Americans, playing to clinch a berth in Brazil this week.

"There will be a lot of tension," Klinsmann conceded. "They thought the 'Snow Game' shouldn't have been played, but we feel that we would have won by an even wider margin if there wasn't snow."

The U.S. can't afford to be drawn into a physical match against Costa Rica because eight American players — including Altidore, Dempsey, midfielder Michael Bradley and goalkeeper Tim Howard — are carrying yellow cards. A second caution will result in a suspension from the game against Mexico.

"Overall I think the guys need to be very disciplined and focused," Klinsmann said. "We hope to get through that game, but by no means are we going to hold back."

Nor, Klinsmann promised, are they looking ahead to the next match with archrival Mexico. After all, there's a fine line between confidence and complacency. And given where the U.S. was seven months ago, that's not a line Klinsmann wants to see blurred.

"I have the approach that the next game is always the biggest one," he said. "This game could put us absolutely in the driver's seat for Brazil. That's why I don't want the players to think, not even for one second, about Mexico in Columbus. I want them just to tune in for San Jose, Costa Rica, and give everything they have.

"Once that game is over on Friday night, then we can turn the page and start talking about other things. That's why I'm saying it's a huge game."